1. Field of the Invention
The present invention relates to a method for preventing deformation on the edge of the cavity of an injection mold cavity from over-polishing.
2. Description of the Prior Art
Multiple plastic injection products, such as housings of mobile phones, digital cameras . . . etc., are manufactured by using an injection mold cavity. One injection mold cavity is usually used for manufacturing thousands of injection products; therefore, the condition of an injection mold cavity affects the quality of the injection products. Normally, a polishing procedure must be applied to the injection mold cavity after a time period of usage, so as to assure the mold surface of the injection mold cavity smoother. However, during the polishing procedure, the mold edge of the injection mold cavity is often deformed due to over-polishing.
Referring to FIG. 1, FIG. 2A, and FIG. 2B, FIG. 1 is a schematic diagram of a conventional injection mold cavity 10. FIG. 2A is a schematic diagram of the deformed edge 12 of the injection mold cavity 10 shown in FIG. 1, FIG. 2B is a schematic diagram of the un-deformed edge 12B of the injection mold cavity 10 shown in FIG. 1. When over-polishing occurs, the unexpected deformation of the edge 12 of the injection mold cavity is approximately the same as shown in FIG. 2A, and the expected edge 12B of the injection mold cavity after manufacturing is shown in FIG. 2B. However, if the deformation continues, the injection mold cavity will eventually affect the injection products.
Referring to FIG. 3, FIG. 3 is a perspective view of the injection product 30 manufactured by the injection mold cavity 10 shown in FIG. 1. The injection product 30 is a front housing of a mobile phone having an assembling edge 32. From the sectional magnified view in FIG. 3, due to the deformation of the edge 12 of the injection mold cavity, the assembling edge 32 of the injection product forms a corresponding raise 33, or called “burr”. The raise 33 is not the expected result when the injection product 30 is manufactured. However, it is not easy to prevent over-polishing from occurring in the conventional injection mold cavities because the deformation of the edge 12 of the injection mold cavities happens quite often. Therefore, the unexpected raise 33 appearing on the assembling edge 32 of the injection product is very common but affects the appearance a lot in the finish goods.